Ham radio
Time relay, the readers, used in the automation devices in the workplace and at home. The device is simple in design, has small dimensions, is reliable in operation, but its main feature — a large range of exposures.
GENERAL PURPOSE PROBE
electrical Work on a modern industrial enterprise impossible without measuring instruments, many of them are very complex.
OBJECTIVE EXAMINER
In the sixth issue of our magazine in 1974 we told about the device “Pulse” for the control of knowledge of students. Practice operating the machine created by the participants NTTM Donetsk Polytechnic Institute, as well as the feedback from readers has convinced authors of the need to improve the design.
TRANSFORMERLESS INCLUSION OF LDS
10 years — 15 ago, the industry was widely released table lamps with fluorescent lamps, designed for a voltage of 127 V. A today 127 V network was preserved only in rare homes. It is clear that the owners of these lamps was now “tied” to expensive and bulky step-down transformers. We offer our readers we developed and tested a device that allows you to include a 127-volt lamp in the network a voltage of 220 V without the step-down transformer.
STEREO HEADPHONES FOR ONE EVENING
The design uses dynamic heads 0,25 GD or similar without any alterations. Ear cushions and pillows are made of a rubber sponge (you can buy in the pharmacy). For heads with a cone diameter of about 55 mm suitable sponge about the size of 155X60X35 mm. First take a piece of pressshpana or solid cardboard the size of 130X130 mm. In it cut a hole and glued it to the head (Fig. 1). Then, in the spongebob ear cushions cut out (or pluck) recess the speaker housing (Fig. 3), and the sponge-cushion (Fig. 2) make the hole oval. Its inner edge is cut from the side adjacent to the ear.
CONTACTLESS CAPACITIVE RELAY
The basis of a capacitive relay — a low-power generator of high frequency such as local oscillator of a radio receiver. To the circuit L1C4 (see diagram) of the connected metal plate sensor. Approached to him the palm of the hand represents the second plate of the capacitor CD. The capacity of such a condenser is the greater, the more area it covers and the smaller the distance between them.
FIVE INSTRUMENTS IN ONE
Perhaps the most difficult stage in the process of creating radiokonstruktor — setting. But if you have even the simplest instrumentation, to establish any electronic device will be much easier. At least, for this job you need avometr, or simply tester. For example, very popular among ham radio uses a simple inexpensive device C-20. But the problem is, he is not entirely comfortable, and this tester is limited. So for those of you who already have such avometr, we propose to improve it by extending the limits of measurement and adding the generator probe with the test transistors.
SPORTS EXAMINER
To the line “Start” suitable for a student with basketball ball in hands, and comes on the panel associated with the starting button of the examiner, the Machine still does not work: it can be switched on only after the button is released.
THE EFFECTS UNIT IS FOR SOLO GUITAR
Before describing the operation of the device as a whole will focus on one of its constituent elements — the Converter of the spectrum of the electrical signal, or “FUZZ”device. To To obtain this effect, it is necessary to enrich the original signal a large number of odd harmonics. There are several ways, and thus the schemes to achieve them. We will stop at the spectrum Converter, which is a ULF with parapremium.
The planetary Rovers
In annually conducted by our magazine national competition “Cosmos” among the many models fantasies occupy a significant place different kinds of self-propelled tools “planetary Rovers”. According to young technicians, they are indispensable transport in the study of nearby planets the astronauts.